In the advancement of the Internet of Things (IoT) applications, widespread uses and applications of devices require higher frequency connectivity to be explored and exploited. Furthermore, the size, weight, power and cost demands for the IoT ecosystems also creates a new paradigm for the hardware where improved power efficiency and efficient wireless transmission needed to be investigated and made feasible. As such, functional microwave detectors to detect and rectify the signals transmitted in higher frequency regions are crucial. This paper reviewed the practicability of self switching diodes as Radio Frequency (RF) rectifiers. The existing methods used in the evaluation of the rectification performance and cut-off frequency are reviewed, and current achievements are then concluded. The works reviewed in this paper highlights the functionality of SSD as a RF rectifier with design simplicity, which may offer cheaper alternatives in current high frequency rectifying devices for application in low-power devices.

1. Bulletin of Electrical Engineering and Informatics
Vol. 8, No. 2, June 2019, pp. 396~404
ISSN: 2302-9285, DOI: 10.11591/eei.v8i2.1413  396
Journal homepage: http://beei.org/index.php/EEI
Self-switching diodes as RF rectifiers: evaluation methods and
current progress
Nor Farhani Zakaria, Shahrir Rizal Kasjoo, Muammar Mohamad Isa, Zarimawaty Zailan, Mohd
Khairuddin Md Arshad, Sanna Taking
School of Microelectronics Engineering, Universiti Malaysia Perlis, Pauh Putra Campus, 02600 Perlis, Malaysia
Article Info ABSTRACT
Article history:
Received Dec 6, 2018
Revised Jan 24, 2019
Accepted Feb 25, 2019
In the advancement of the Internet of Things (IoT) applications, widespread
uses and applications of devices require higher frequency connectivity to be
explored and exploited. Furthermore, the size, weight, power and cost
demands for the IoT ecosystems also creates a new paradigm for the
hardware where improved power efficiency and efficient wireless
transmission needed to be investigated and made feasible. As such,
functional microwave detectors to detect and rectify the signals transmitted
in higher frequency regions are crucial. This paper reviewed the
practicability of self switching diodes as Radio Frequency (RF) rectifiers.
The existing methods used in the evaluation of the rectification performance
and cut-off frequency are reviewed, and current achievements are then
concluded. The works reviewed in this paper highlights the functionality of
SSD as a RF rectifier with design simplicity, which may offer cheaper
alternatives in current high frequency rectifying devices for application in
low-power devices.
Keywords:
ATLAS silvaco
IoT application
Nonlinear device analysis
Rectification performance
Self-switching device
Copyright © 2019 Institute of Advanced Engineering and Science.
All rights reserved.
Corresponding Author:
Nor Farhani Zakaria,
School of Microelectronics Engineering,
Universiti Malaysia Perlis,
Pauh Putra Campus, 02600 Perlis, Malaysia.
Email: norfarhani@unimap.edu.my
1. INTRODUCTION
Advances in the innovation and development of the semiconductor industry following the Moore’s
law classical scaling [1] had allowed the industry to double the processing power every 18 months until the
last decade, where it is impossible to continually increase both frequency and doubled the transistor number
in a chip because of the fundamental thermal limit in the ICs. This has started the second More than Moore’s
era with equivalent scaling [2]. The approaches of this era which introduced the usage of strained silicon,
high-κ/metal gate, FinFET, and other semiconductor material (e.g. Germanium) had increased the
performance of transistors and the non-digital functionalities e.g. radio frequency (RF) communication,
power control and passive components [3] which bring us to the onset of the internet technologies era by the
theme of Internet of Things (IoT). The focus of the semiconductor industry in this era has changed to the
third phase of scaling, the three dimensional (3D) power scaling where the focus has been changed from
shrinking individual chips to emphasizing capability integration and power consumption reductions [4, 5]
which aim for mobile, high connectivity and low power consumption devices. This scaling is in-line with the
roadmap of IoT which aims for miniaturization, power-efficient electronics, and available spectrum in the
year 2020 [6]. The size, weight, power and cost (SWaP-C) demands for the IoT ecosystems also creates a
new paradigm for the hardware where smart power management, improved power efficiency, wireless power
transmission and energy harvesting needed to be investigated and made feasible for IoT applications [7].One
of the solutions for mobile, rechargeable device is by wireless power transfer (WPT) by harvesting ambient

2. Bulletin of Electr Eng and Inf ISSN: 2302-9285 
Self-switching diodes as RF rectifiers: evaluation methods and current progress (Nor Farhani Zakaria)
397
energy from surroundings in micro or nano-scale power source [8]. The harvester in general, heavily depends
on the diode, which enables switching-type conversion e.g. direct current to direct current (DC–DC) or
alternating current to direct current (AC–DC) conversion [9]. These diodes have been used in various
harvesters as rectifier where it reacts differently depending on the sign of the voltage across it. The capability
of the rectifying diodes to be used in this microwave region need to be carefully examined to ensure that the
electron transport in the device can cope with the high transition rate between the positive and the
negative cycles.
The uses of conventional pn junction diodes as rectifier are irrelevant for this high frequency
application because of the phase lag caused by the slower transition of minority carriers [10]. Hence, unipolar
or majority carrier devices such as tunnel diodes, back diodes, and Schottky diodes are utilized in high
frequency region. However, because of greater susceptibility to RF burnout, circuit complications, and
fabrication difficulties, tunnel and back diodes have not found as wide acceptance as mixers and detectors at
microwave frequencies [11]. Most widely used and marketed rectifier in the microwave region is the
Schottky diode which is formed by depositing a whisker-like metal on a semiconductor. This
semiconductor-metal junction creates a barrier (known as Schottky barrier) between both materials which
results in rectifying behavior [12]. Rectification using Schottky devices may reach high frequencies but it has
limitations in term of sophisticated nano-gates fabrication process which often results in parasitic effects
[13, 14]. Furthermore, the coupling of a Schottky device with antennas and waveguide as well as the
fabrication of large arrays also pose additional engineering issues [15].
A less explored device with promising capability for zero-bias high frequency detection, the
self-switching diode (SSD) has recently introduced by Song et al. [16]. The SSD is one type of planar
unipolar device, which is more adequate in term of fabrication complexity compared to the most used
Schottky diode where it does not involves junctions, doping, and third gate terminal [17]. The planar
structure of the SSD can reduced the intrinsic device’s parasitic capacitance for high-frequency operations
[18]. The fabrication simplicity and rectification capability of SSD make it a suitable candidate for a low cost
high-frequency detectors.
This paper provides insights into the works related to the rectification performance parameters of
SSD and its cut-off frequency fc detection. First, we provide an explanation on the rectification principle in a
general square law diode detector to have a better view on the parameters affecting the rectification
performance in non-linear devices. Then, we introduced the typical structure of an SSD and its operational
principle to understand the general behavior of electron and current in the structure. Then, we reviewed
published works that related to the evaluation and improvements of the rectification performance and fc of
the SSD. Finally, we concluded the performance and suitability of a SSD as a RF rectifier.
2. NONLINEAR ANALYSIS OF DETECTOR DIODES
An ideal current-voltage (I-V) characteristic of a square-law detector diode has a nonlinear I-V
characteristics, and can be analyzed using a nonlinear device analysis, where I is the function of V:
)
(V
f
I  (1)
The total inputs of the diodes can be from the RF signal and DC bias where V across the diode are
the addition of applied DC bias voltage Vo and RF input of vRF=Acos (ωt), where A is the amplitude of the
input RF signal:
RF
o v
V
V 
 (2)
Expanding (2) using Taylor Series [19-20] with evaluation at Vo (a=Vo), function f (V) becomes:
n
RF
n
o
n
n
o
n
o
n
v
n
V
f
V
V
n
V
f
V
f 








0
)
(
0
)
(
!
)
(
)
(
!
)
(
)
( (3)
Substituting (3) in (1) resulted in the total I of
)
(
)
2
(
2
)
1
(
!
..
!
2
!
1
n
n
RF
RF
RF
o f
n
v
f
v
f
v
I
I 



 (4)

3.  ISSN: 2302-9285
Bulletin of Electr Eng and Inf, Vol. 8, No. 2, June 2019 : 396 – 404
398
where Io=function of Vo [Io=f(Vo)] and f(n)=nth order derivatives of the function Vo. Substituting vRF=Acos
(ωt) in (4) yields;
)
(
)
2
(
2
)
1
(
!
...
!
2
!
1
n
n
o f
n
t)]
[Acos(
f
t)]
[Acos(
f
t)
Acos(
I
I







 (5)
By using power reduction formulas derived from the double-angle and half-angle formulas [21], (5) can be
rewrite as:
...
)
cos(
..
)
3
(
8
3
)
1
(
..
)
4
(
64
4
)
2
(
4
2























 t
B
f
A
Af
A
f
A
f
A
I
I o 


 


 




 



 

(6)
where bracket A refers to the rectified current Δi, and the later bracket, B in (6) attributed by the RF related
current. Only the first term of Δi is significant in small-signal approximation, thus the rectified DC voltage Δv
is equal to
)
1
(
)
2
(
2
)
1
(
4 f
f
A
f
i
i
R
v D 




 (7)
where: RD=1/f (1)
=differential resistance of the diode
A=the amplified input signal
f (1)=
derivatives of the I-V function (1st order)
f (2)=
derivatives of the I-V function (2nd order)
f (2)
is also known as the bowing coefficient in the I-V function [22, 23].
The rectification performance of nonlinear devices can then be calculated using the curvature
coefficient γ, defined as the ratio of f (2)
to f (1)
)
1
(
)
2
(
f
f

 (8)
which relates to Δv in (7). The rectifying capabilities can also be quantified using the current responsivity β
which indicates the conversion capability to rectify current. In a square law regime where rectified current
varies linearly to the RF power, β is constant and equal to the quadratic responsivity β0 [24] which can be
predicted from the I-V characteristics where



2
1
0 
 (9)
For an effective rectification performance at zero-bias, β0 above 3.5 V-1
is desired [25, 26].
3. OPERATIONAL PRINCIPLE OF SSD
A typical structure of a SSD is shown in Figure 1(a). The asymmetrical structure between two
electrodes can be realized with a simple lithography process. The nonlinear behavior of the device can be
obtained by controlling the electric field independent zone (depletion region) of the asymmetric channel
between two electrodes as shown in Figure 1(b). The channel is largely depleted when no voltage is applied
across it because of the surface states at the etched boundaries. At positive bias, the depletion region inside
the channel decreases allowing more electrons to pass across the channel see Figure 1(c). And in negative
bias, the depletion zone inside the channel increases, hence completely pinching-off the channel preventing
the flow of electrons through the channel as shown in Figure 1(d). This electrical behavior will result in a
nonlinear I-V characteristic, where it is similar to a conventional p-n diode but in the absent of any doping
junction and barrier structure.

4. Bulletin of Electr Eng and Inf ISSN: 2302-9285 
Self-switching diodes as RF rectifiers: evaluation methods and current progress (Nor Farhani Zakaria)
399
4. ELECTRICAL CHARACTERIZATION OF SSD AND RECTIFICATION
PERFORMANCE EVALUATION
Owing to the switching principle of SSD, which is based on the depletion region formed in the
asymmetrical channel, the thickness and shape of the depletion region in the channel can be varied to alter
the electrical characteristics of the device. Due to that, many research works were conducted on the
characterization of SSD using various structural parameters see Figure 2 in various materials and structures
to control the I-V characteristics of the device.
Figure 1. (a) Scanning electron micrograph of a
typical SSD, (b) shows the depletion region formed close to
the etched boundaries. Depending on the sign of the applied
voltage the effective channel width will increase, (c) or
reduce, (d) Giving rise to the diode-like characteristics [16]
Figure 2. The structural parameters involved
in characterization of SSD
Among them are the variations of the channel width W [16], [27−31], channel length L [16],
[28−32], trench width Wt [29−35], temperature T [16], [27], [29], [33], [36], [37], and dielectric permittivity
εr [34, 36-38]. In addition, the usage of smallest possible Wt of 5 nm [28] was proposed for future
technology design. Furthermore, studies on the shape of the dielectric channel were also reported and
concluded [38, 39]. These evaluations on particular structural parameter had assisted in term of
understanding the behaviour of the depletion region and improvement of the I-V characteristics (e.g. forward
current Ifwd, threshold voltage Vth, and leakage current Ileak) in SSD as exampled in Table 1 for InGaAs
based SSD [29] (Note that, these behaviours might be varied in different substrate and structure). Thus, the
understandings of the electrical behaviours of the SSD are crucial because it highly contributes to the γ which
shows the rectification performance of non-linear device as explained in Section 2.
Table 1. Electrical behaviour of InGaAs SSD in various structural parameter variations
Increased Parameters Treshold Voltage Vth Forward Current Ifwd Leakage Current Ileak
Channel Length L Increase Decrease Decrease
Trench Width Wt Increase Decrease -
Channel Width W Decrease Increase Increase
Dielectric Permittivity εr Decrease Increase -
Temperature T Decrease Increase Increase
With the knowledge of the relations in the structural parameters to the electrical behaviors, the peak
of γ can be predicted and the I-V characteristics of the device can be controlled by variation of these
structural parameters to obtain efficient zero-bias rectification performance [29]. The rectification
performance of SSD can be evaluated in term of β obtained from the γ of the device. However, in some
published works, the evaluation of the rectification performance is represented by voltage sensitivity (instead
of current responsivity β) which is represented by the value of γ/4 [40].
5. EVALUATION OF CUT-OFF FREQUENCY
Device modelling of SSD has been introduced by using MOSFET square law as the basis, with
model assumptions of total capacitance C and series resistance RS values in SSD [41]. This has enabled the

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400
theoretical calculation of fc, direct from the structural parameters and I-V characteristics using the general
equation of
fc=1/(2πRsC) [29, 41].
The fc evaluation by means of simulation can also be conducted by using AC transient analysis in
device simulators where the AC signals are assigned to imitate the RF waves absorbed by the diodes
[28-29, 38]. The resulted mean current from the AC transient analysis can then be calculated to determine fc.
The fc evaluation using experimental works using RF network analyzer with an array of SSDs
connected to rectenna were conducted using 18 parallel SSDs [40], using 43 SSDs [42], and by using 2000
SSDs in array configuration, by coupling to a bow-tie rectenna [23] and a spiral antenna [43]. Proper choose
of the SSDs in array configurations can reduced the value of Rs and can improve the impedance matching
between the antennas and the device.
6. SSD USING VARIOUS MATERIALS
Apart from the structural characterization, researches on SSD using various materials were done in
attempts to increase β and fc of the device as shown in Table 2. The voltage sensitivity of the device is
represented by the value of γ/4 (refer Section 4) [40], and the Noise Equivalent Power (NEP) is defined as the
noise power density over the detection sensitivity [23] where it is represented by the minimum detectable
power per square root bandwidth (W/Hz1/2
) [44]. Researches using various materials were conducted not only
by employing semiconductor materials, but also by using other green materials [45] such as P3HT [46] and
MOS2 [47], but there are no records on the mobility and fc. However, SSD fabricated on graphene possess a
large number of carrier density, but having a low mobility value, up to 1400 cm2
/Vs with largest recorded
detection at 67 GHz, as shown in Table 2.
Table 2. Self-switching devices using various materials and their electrical performances
Institution Material
Carrier Density,
Mobility
Voltage
Sensitivity
Noise
Equivalent
Power (NEP)
Cut-off
Frequency fc
Representative Image Ref.
Fujitsu
Lab., Japan
ZnO
NA,
0.35 cm2
/Vs
NA NA 50 Hz [32]
Chalmers
Univ. of
Tech.,
Sweden
&
Linköping
Univ.,
Sweden
hydrogen
-
intercalat
ed
epitaxial
graphene
on SiC
NA ,
~1400 cm2
/Vs
NA
(γ=0.35 V-
1
)
~ 2.2 nW/Hz1/2 67 GHz at
zero-bias
[48]
Univ. of
Salamanca,
Spain
InAlAs/
InGaAs
0.3×1012
cm-2
,
NA
NA NA 2 THz [28]
Univ. of
Lille,
France
InAs/AlG
aSb
1.5 x 1012
cm-2
,
26000 cm2
/Vs
NA
NA
65
pW/Hz1/2
NA
50 GHz
600 GHz
[42]
Univ. of
Manchester
, U.K
GaAs/
AlGaAs
5.95 x 1011
cm-2
,
~7000 cm2
/Vs
(T=300K)
5.55 x 1011
cm-2
,
~72000 cm2
/Vs
(T=77 K)
150
mV/mW
(Sensitivity
at zero-
bias)
300
mV/mW
(sensitivity
at 10 nA
bias)
330 pW/Hz1/2
1.5 THz [23]
Inst. of GaN/AlG 1.1 x 1013
cm-2
, NA NA 320 GHz [49]

6. Bulletin of Electr Eng and Inf ISSN: 2302-9285 
Self-switching diodes as RF rectifiers: evaluation methods and current progress (Nor Farhani Zakaria)
401
Institution Material
Carrier Density,
Mobility
Voltage
Sensitivity
Noise
Equivalent
Power (NEP)
Cut-off
Frequency fc
Representative Image Ref.
Electronics
,
Microelectr
onics
&Nanotech
., France
aN 1800 cm2
/Vs
Univ. of
Manchester
, U.K
InP/InGa
As/InP
1.0 x 1016
m-2
,
450000 cm2
/Vs
(T=4.2 K)
75 mV/mW NA 110 GHz [40]
The mobility of SSD fabricated using ZnO, ITO, and SOI are very low with mobility of 0.35, 14.5,
and 400 cm2
/Vs, respectively, and with only fc of 50 Hz recorded in ZnO. In contrast, SSD fabricated on
III-V materials such as InGaAs, AlGaAs, AlGaSb, and AlGaN have remarkably high mobility with the
highest observed in InGaAs/InP with value of 450000 cm2
/Vs. The highest detection frequency of SSD has
been recorded using InGaAs at 2 THz by simulation. Nevertheless, by experimental works, the highest
detection frequency of 1.5 THz has been observed in AlGaAs. With prudent considerations on the device
material, the mobility of the device may be improved and contributes to higher fc.
7. RECTIFICATION AND CUT-OFF FREQUENCY PERFORMANCE
As to our knowledge, the highest β value of 15 V-1
was achieved using InGaAs/InAlAs based SSD
with parameter of W=70 nm, L=0.8 μm, and Wt=50 nm with γ peaks at zero-bias [29]. This value indicates
high efficiency of the energy conversion in the rectification process (minimal β of 3.5 V-1
are required for
efficient conversion process). fc value of ~80 GHz has been achieved using the same structure using Silvaco
ATLAS simulator. Highest fc value of 1.5 THz was achieved by experimental works using GaAs/AlGaAs
substrate, with 150 mV/mW sensitivity at zero-bias [23], showing the capability of SSD to works up to the
THz region. By Monte Carlo simulation, fc of 2 THz has been achieved using InGaAs/InAlAs substrate with
parameters of W=50 nm, L=100 nm, and Wt=5 nm. However, the etching process of 5 nm channel might be a
big hurdle in nowadays practical application.
8. CONCLUSION
Since SSD was first introduced in 2003, many research works were conducted to improve the
rectification performance and cut-off frequency of the device. With prudent considerations on the structural
parameters and materials, it is proven that the SSDs are capable to efficiently work as rectifiers at high
frequency region. The simplicity of the design and process used in these devices may offer cheaper
alternatives in current high frequency rectifying devices for application in low-power devices.
ACKNOWLEDGEMENTS
The author would like to acknowledge the support from the Fundamental Research Grant Scheme
(FRGS) under a grant number of FRGS/1/2017/STG02/UNIMAP/02/2 (FRGS 9003-00622) from the
Ministry of Higher Education Malaysia.
REFERENCES
[1] G. E. Moore, “Cramming more components onto integrated circuits”. Proceedings of the IEEE. vol. 86, no 1,
pp. 82-85. January 1998.
[2] A. B. Kahng, "Scaling: More than Moore's law," in IEEE Design & Test of Computers, vol. 27, no. 3, pp. 86-87,
May-June 2010.
[3] N. Collaert et al., "Beyond-Si materials and devices for more Moore and more than Moore applications," 2016
International Conference on IC Design and Technology (ICICDT), Ho Chi Minh City, 2016, pp. 1-5.
[4] E. P. DeBenedictis, M. Badaroglu, A. Chen, T. M. Conte, and P. Gargini, “Sustaining Moore's law with 3D chips”,
Computer, vol. 50, no. 8, pp. 69-73, 2017.
[5] Semiconductor Association, The International Technology Roadmap for Semiconductor (ITRS) 2.0, Executive
report, 2015.

7.  ISSN: 2302-9285
Bulletin of Electr Eng and Inf, Vol. 8, No. 2, June 2019 : 396 – 404
402
[6] X. Jia, Q. Feng, T. Fan and Q. Lei, "RFID technology and its applications in Internet of Things (IoT)," 2012 2nd
International Conference on Consumer Electronics, Communications and Networks (CECNet), Yichang, 2012,
pp. 1282-1285.
[7] J. Gubbi, R. Buyya, S. Marusic, and M. Palaniswami, “Internet of Things (IoT): A vision, architectural elements,
and future directions”, Future generation computer systems, vol. 29, no. 7, pp. 1645-1660, September 2013.
[8] C. R. Valenta and G. D. Durgin, “Harvesting wireless power: Survey of energy-harvester conversion efficiency in
far-field, wireless power transfer systems”, in IEEE Microwave Magazine, vol. 15, no. 4, pp. 108-120, June 2014.
[9] U. K. Mishra and J. Singh, Field effect transistors. InSemiconductor Device Physics and Design, Springer
Netherlands, 2008, pp. 356-432.
[10] Y. Anand and W. J. Moroney, “Microwave mixer and detector diodes”, in Proceedings of the IEEE, vol. 59, no. 8,
pp. 1182-1190. August 1971.
[11] M. A. Laughton and D. F. Warne. "Power semiconductor devices." Electrical engineer’s reference book, 2003,
pp. 25-27.
[12] Z. Jingtao, Y. Chengyue, G. Ji, and J. Zhi, “Planar InP-based Schottky barrier diodes for terahertz applications”,
Journal of Semiconductors, vol. 34, no. 6, p. 064003, June 2013.
[13] D. Dragoman and M. Dragoman, “Geometrically induced rectification in two-dimensional ballistic nanodevices”,
Journal of Physics D: Applied Physics, vol. 46, no. 5, p. 055306, January 2013.
[14] V. Milanovic, M. Gaitan, J. C. Marshall and M. E. Zaghloul, "CMOS foundry implementation of Schottky diodes
for RF detection," in IEEE Transactions on Electron Devices, vol. 43, no. 12, pp. 2210-2214, Dec. 1996.
[15] C. B. Vining, “An inconvenient truth about thermoelectrics”, Nature materials, vol. 1, no. 8(2), p. 83,
February 2009.
[16] A. M. Song, M. Missous, P. Omling, A. R. Peaker, L. Samuelson, and W. Seifert, “Unidirectional electron flow in a
nanometer-scale semiconductor channel: A self-switching device”, Applied Physics Letters, vol. 83 no. 9,
pp. 1881-1883, September 2003.
[17] A. M. Song, I. Maximov, M. Missous, and W. Seifert, “Diode-like characteristics of nanometer-scale
semiconductor channels with a broken symmetry”, Physica E: Low-dimensional Systems and Nanostructures,
vol. 21, pp. 1116-1120, March 2004.
[18] C. Balocco, S. R. Kasjoo, L. Q. Zhang, Y. Alimi, and A. M. Song, “Low-frequency noise of unipolar
nanorectifiers”, Applied Physics Letters, vol. 99, no. 11, p.113511, September 2011.
[19] Y. Ren, B. Zhang, and H. Qiao, “A simple Taylor-series expansion method for a class of second kind integral
equations”, Journal of Computational and Applied Mathematics, vol. 110, pp. 15-24, October 1999.
[20] M. Dougherty and J. Gieringer, First Year Calculus: For Students of Mathematics and Related Disciplines, 2012.
[21] C. Y. Young, Trigonometry, 3rd ed., New Jersey: John Wiley & Sons, 2011.
[22] D. M. Pozar, Microwave Engineering, 3rd ed. Transmission Lines and Waveguides, pp. 143-149, 2005.
[23] C. Balocco, S. R. Kasjoo, X. F. Lu, L. Q. Zhang, Y. Alimi, S. Winnerl, and A. M. Song, “Room-temperature
operation of a unipolar nanodiode at terahertz frequencies”, Applied Physics Letters, vol. 98, no. 22, p. 223501,
May 2011.
[24] S. Hemour and K. Wu, "Radio-Frequency Rectifier for Electromagnetic Energy Harvesting: Development Path and
Future Outlook," in Proceedings of the IEEE, vol. 102, no. 11, pp. 1667-1691, 2014.
[25] P. Periasamy, J. J. Berry, A. A. Dameron, J. D. Bergeson, D. S. Ginley, R. P. O'Hayre RP et al., “Fabrication and
characterization of MIM diodes based on Nb/Nb2O5 via a rapid screening technique”, Advanced Materials, vol. 23,
pp. 3080-5, July 2011.
[26] M. L. Chin, P. Periasamy, T. P. O'Regan, M. Amani, C. Tan, R. P. O'Hayre et al., “Planar metal–insulator–metal
diodes based on the Nb/Nb2O5/X material system”, Journal of Vacuum Science & Technology B, Nanotechnology
and Microelectronics: Materials, Processing, Measurement, and Phenomena, vol. 31(5) p. 051204,
September 2013.
[27] G. Farhi, E. Saracco, J. Beerens, D. Morris, S. A. Charlebois, and J. P. Raskin, “Electrical characteristics and
simulations of self-switching-diodes in SOI technology”, Solid-State Electronics, vol. 51, no. 9, p. 1245-1249.
September 2007
[28] J. Mateos, A. M. Song, B. G. Vasallo, D. Pardo, and T. González, “THz operation of self-switching nano-diodes
and nano-transistors” International Society for Optics and Photonics, Nanotechnology II, vol. 5838, pp. 145-154,
June 2005.
[29] N. F. Zakaria, S. R. Kasjoo, Z. Zailan, M. M. Isa, S. Taking, and M. K. M. Arshad ,”Permittivity and Temperature
Effects on Rectification Performance of Self-Switching Diodes with Different Geometrical Structures Using
Two-Dimensional Device Simulator”, Solid-State Electronics, vol.138, pp 16–23, 2017.
[30] N. F. Zakaria, S. R. Kasjoo, Z. Zailan, M. M. Isa, M. K. M. Arshad, and S. Taking,” Rectification performance of
self-switching diode in various geometries using ATLAS simulator”, 3rd International Conference on Electronic
Design (ICED), Phuket, 2016, pp 361-364.
[31] Z. Zailan, N. F. Zakaria, M. M. Isa, S. Taking, M. K. M. Arshad, and S. R. Kasjoo, "Characterization of
self-switching diodes as microwave rectifiers using ATLAS simulator," 2016 5th International Symposium on
Next-Generation Electronics (ISNE), Hsinchu, 2016, pp. 1-2. 10.1109/ISNE.2016.7543286
[32] I. Soga, A. Komuro, and O. Tsuboi, “Rectifying characteristics of thin film self-switching devices with ZnO
deposited by atomic layer deposition”, Electronics letters, vol. 48, no. 15 pp. 914-916, July 2012.

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[33] I. Iñiguez-De-La-Torre, H. Rodilla, J. Mateos, D. Pardo, A. M. Song, and T. González, “Terahertz tunable
detection in self-switching diodes based on high mobility semiconductors: InGaAs, InAs and InSb”, Journal of
Physics: Conference Series 2009, vol. 193, No. 1, p. 012082, 2009.
[34] G. Farhi, D. Morris, S. A. Charlebois, and J. P. Raskin, “The impact of etched trenches geometry and dielectric
material on the electrical behaviour of silicon-on-insulator self-switching diodes”, Nanotechnology, vol. 22, no. 43,
p. 435203, October 2011.
[35] S. Garg, A. Garg, S. Bansal, A. Chaudhary, A. K. Singh and S. R. Kasjoo, "Effect of filling dielectric in etched
trenches of novel unipolar nanodiode," 2016 International Conference on Microelectronics, Computing and
Communications (MicroCom), Durgapur, 2016, pp. 1-3.
[36] Z. Zailan, S. R. Kasjoo, N. F. Zakaria, M. M. Isa, M. K. M. Arshad and S. Taking, "Rectification performance of
self-switching diodes in silicon substrate using device simulator," 2016 3rd International Conference on Electronic
Design (ICED), Phuket, 2016, pp. 373-376.
[37] N. F. Zakaria, Z. Zailan, M. M. Isa, S. Taking, M. K. M. Arshad and S. R. Kasjoo, "Permittivity and temperature
effects to rectification performance of self-switching device using two-dimensional simulation," 2016 5th
International Symposium on Next-Generation Electronics (ISNE), Hsinchu, 2016, pp. 1-2.
[38] K. Y. Xu, X. F. Lu, A. M. Song, and G. Wang, “Enhanced terahertz detection by localized surface plasma
oscillations in a nanoscale unipolar diode”, Journal of Applied Physics, vol. 103, no. 11, p. 113708, June 2008.
[39] I. E. Cortes-Mestizo, E. Briones, J. Briones, R. Droopad, M. Perez-Caro, S. McMurtry et. al., “Study of
InAlAs/InGaAs self-switching diodes for energy harvesting applications”, Japanese Journal of Applied Physics,
vol. 55, no. 1, p. 014304, December 2015.
[40] C. Balocco, A. M. Song, M. Åberg, A. Forchel, T. González, J. Mateos et al., “Microwave detection at 110 GHz by
nanowires with broken symmetry”, Nano Letters, vol. 5, no. 7, p.1423-7, July 2005.
[41] M. Aberg and J. Saijets, "DC and AC characteristics and modeling of Si SSD-nano devices," Proceedings of the
2005 European Conference on Circuit Theory and Design, 2005., Cork, Ireland, 2005, pp. I/15-I/18 vol. 1.
[42] A. Westlund, P. Sangaré, G. Ducournau, P. Å. Nilsson, C. Gaquiere, L. Desplanque et al., “Terahertz detection in
zero-bias InAs self-switching diodes at room temperature”, Applied Physics Letters, vol. 103, no. 13, p. 133504,
September 2013.
[43] S. R. Kasjoo and A. M. Song, “Terahertz detection using nanorectifiers”, in IEEE Electron Device Letters, vol. 34,
no. 12, pp. 1554-1556, December 2013.
[44] S. Leclercq, “Discussion about Noise Equivalent Power and Its Use for Photonnoise Calculation”, Report On FOV
Optics And Bolometer Projects For The 30m Telescope, International Research Institute For Radio Astronomy
(IRAM), pp. 1-15, 2007.
[45] S. R. Kasjoo, Z. Zailan, N. F. Zakaria, M. M. Isa, M. K. M. Arshad, and S. Taking, “An overview of self-switching
diode rectifiers using green materials”, AIP Conference Proceedings, vol. 1885, no. 1, p. 020257, September 2017.
[46] J. Kettle, R. M. Perks, and R. T. Hoyle, “Fabrication of highly transparent self-switching diodes using single layer
indium tin oxide”, Electronics Letters, vol. 45, no. 1, pp. 79-81, January 2009.
[47] F. Al-Dirini, M. A. Mohammed, F. M. Hossain, T. A. Nirmalathas, and E. Skafidas, “All-graphene planar
double-quantum-dot resonant tunneling diodes”, in IEEE Journal of the Electron Devices Society, vol. 4, no.1,
pp.30-39, January 2016.
[48] A. Westlund, M. Winters, I. G. Ivanov, J. Hassan, P. Å. Nilsson, E. Janzén et al., “Graphene self-switching diodes
as zero-bias microwave detectors”, Applied Physics Letters, vol. 106, no. 9, p. 093116, March 2015.
[49] P. Sangaré, G. Ducournau, B. Grimbert, M. Faucher and C. Gaquière, "Zero-bias GaN implanted Self-Switching
Diode coupled with bow-tie antenna for THz applications," 2014 44th European Microwave Conference, Rome,
2014, pp. 806-809.
BIOGRAPHIES OF AUTHORS
Nor Farhani Zakaria received her B. Eng degree in Electronic Engineering in 2006 and the M.
Sc. in Engineering (Bioelectronics) from Tokyo University of Technology, Japan in 2008. She is
a lecturer in Universiti Malaysia Perlis (UniMAP), and currently pursuing her PhD in
Microelectronic Engineering at UniMAP in the area of electrical characterization and modelling
of semiconductor materials and devices, with interest in high frequency devices.

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Bulletin of Electr Eng and Inf, Vol. 8, No. 2, June 2019 : 396 – 404
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Shahrir R. Kasjoo received the Ph.D. degree in electrical and electronic engineering from the
University of Manchester, United Kingdom, in 2012. He is now with the School of
Microelectronic Engineering, Universiti Malaysia Perlis, Malaysia, as a Senior Lecturer.
Muammar Mohamad Isa received his B. Eng. (Hons.) Electrical & Electronic Engineering from
Universiti Tenaga Nasional in 2002 before he joined Silterra (M) Sdn. Bhd. as a Process
Engineer. Later, he pursued his M. Sc (Microelectronics) at Universiti Kebangsaan Malaysia in
2004 before he joined Kolej University Kejuruteraan Utara Malaysia (KUKUM) as a full-time
academician. After his three years of experience as Lecturer there, he pursued his PhD in
Electrical & Electronic Engineering at The University of Manchester and received his degree in
2012. His works in the development of high-frequency and low noise devices for satellite
communication have been recognized by ANGKASA in 2012. He currently works on high-speed
and low-noise device fabrication and characterization for future high-speed, high-frequency and
low-noise applications. He also works on the design and fabrication of micro-antenna for early
cancer cell detection. He can be contacted at muammar@unimap.edu.my.
Zarimawaty Zailan received the B.Eng. degree in Microelectronics Engineering in 2008, the
M.Sc. degree in Microelectronics Engineering in 2012 and obtained her PhD degree in
Microelectronics Engineering in 2018 from the Universiti Malaysia Perlis, Malaysia. Her
doctoral research involved the design and characterization of self-switching diode and planar
barrier diode as high frequency rectifiers. She is currently a senior lecturer in Faculty of
Engineering Technology, Universiti Malaysia Perlis, Malaysia.
Mohd Khairuddin Md Arshad is an Associate Professor at the School of Microelectronic
Engineering, Universiti Malaysia Perlis. He received Doctor of Engineering Science from the
Université Catholique de Louvain (UCL), Louvain-la-Neuve, Belgium in 2013. Prior to joining
UniMAP in 2005, he had worked at Agilent Technologies (M) Sdn. Bhd, Penang, where he was
the Product Engineer for the Motion Control Department, manufacturing various printers’
sensors. Then, he joined ON Semiconductor (M) Sdn. Bhd, Senawang, Malaysia, as the
postgraduate researcher involved in developing Under-Bump-Metallurgy (UBM) for Flip-Chip
Packaging, Later, for his doctorate study, he involved in developing ultra-thin body and thin
buried oxide (UTBB) for advanced low power mobile transistor application. His current research
is related to Field-Effect device technology and biosensors. With his experienced in
semiconductor packaging, fabrication process, and device technology, gained at industry and
academic, he has received various national and two Royal Society–Newton Ungku Omar
mobility grants, and regular Journal reviewer for Biosensors & Bioelectronics, Scientific Report,
Materials Science and Engineering C and several other Journals. He is one of the founding
members and currently Chair for IEEE Malaysia Section Sensors & Nanotechnology Joint
Councils Chapter (CH10820). He is also a Professional Engineer and serves as Engineering
Accreditation panel for Board of Engineer Malaysia (BEM) and Malaysian Qualifications
Agency (MQA).
Sanna Taking received the B.Eng. degree in Electrical, Electronic, and Systems Engineering in
2001 and the M.Sc. degree in Microelectronics in 2003 from the Universiti Kebangsaan
Malaysia, Malaysia. She obtained her PhD degree in Electronics and Electrical Engineering in
2012 from the University of Glasgow, United Kingdom. Her doctoral research involved the
development of GaN-based technology for high-frequency high-power applications. Since 2004,
she is a lecturer with the Universiti Malaysia Perlis, Malaysia. Her current research interests
include the development of new types of Gallium Nitride-based high electron mobility
transistors for power electronics and for RF applications, Gallium Nitride-based light-emitting
diodes, Silicon-based power semiconductor devices and simulation-based power
amplifier designs.